CORDLESS, POWERED SURGICAL TOOL

• US 20040022527A1
• Filed: 08/01/2002
• Published: 02/05/2004
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Philipp, Chris, Walen, James G., Carusillo, Steve, Nic, David M.
• Granted Patent: US 6,960,894 B2
• Time in Patent Office: Days
• US Class Current: 388/800
• CPC Class Codes: A61B 17/142 with reciprocating saw blades, e.g. with cutting edges at the distal end of the saw blades
• CPC Class Codes: A61B 17/1626 Control means; Display units
• CPC Class Codes: A61B 2017/00367 Details of actuation of instruments, e.g. relations between pushing buttons, or the like, and activation of the tool, working tip, or the like
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: Y10S 388/937 Hand tool

Abstract

A powered tool for performing surgical procedures. The tool includes a handpiece in which a power generating unit is housed. A control member is mounted to the handpiece. The control member is mounted to the handpiece so that the orientation of the control member can be selectively set relative to the point to which it is mounted to the handpiece and so it can move relative to a reference point on the handpiece. A control module monitors the orientation of the control member and its position relative to the reference point. Based on the control member orientation and position, the control module generates signals to regulate the operation of the power generating unit. When the power generating unit is a motor, the control module generates signals to ensure that the maximum speed at which the motor can be driven is less than the no load speed.

Claims

1. A powered surgical saw, said saw including:

a handpiece;

a motor disposed in said handpiece, said motor having a rotating shaft and configured to rotate the shaft at a variable speed in response to a variable energization signal wherein said motor has a no load speed;

a linkage assembly mounted to said handpiece and connected to said motor shaft for converting the rotary movement of said motor shaft to a back-and-forth movement;

a coupling assembly mounted to said handpiece and connected to said linkage assembly to engage in back-and-forth movement in response to actuation of said linkage assembly by said motor shaft, said coupling assembly constructed to removably receive a saw blade so that the saw blade engages in back-and-forth movement with said coupling assembly;

a battery connected attached to said handpiece to provide energization power to said motor;

a user-actuated control member moveably mounted to said handpiece, said control member having an initial position and a final position and a plurality of user-selected intermediate positions between the initial and final positions, each said position being representative of a user selected motor speed; and

a speed regulator mounted to said handpiece, said speed regulator being connected to;

said control member to monitor the movement of said control member;

said battery; and

to said motor for applying the energization signal to said motor and for monitoring the shaft speed, said speed regulator configured to, based on the movement of said control member and the motor speed, apply the energization signal to said motor so that said operates at a speed based on the position of said control member as the load applied to the motor varies; and

a speed limiting assembly integral with at least one of said control member or said speed regulator, wherein said speed limiting assembly is configured to limit the speed of said motor so that, when said control member is in the final position, said speed regulator causes said motor to run at a maximum speed that is less than the no load speed.

2. The powered surgical saw of claim 1, wherein said speed limiting assembly is associated with said control member.

3. The powered surgical saw of claim 2, wherein:

said control member has a full speed position;

said speed regulator is configured so that when said control member is in the full speed position, said speed regulator causes said motor to run at the no load speed; and

said speed limiting assembly includes a mechanical member connected to said handpiece positioned adjacent said control member so as to prevent said control member from being displaced from the final position to the full speed position.

4. The powered surgical saw of claim 2, wherein:

said control member is part of a trigger assembly and said trigger assembly further includes a moveable sensed element internal to said handpiece, wherein said sensed element is moveable from a first position to a second position;

said speed regulator includes a sensor configured to monitor the movement of said sensed element and to regulate the energization of said motor so that;

when said sensed element is in the first position, the motor is actuated to run at a slow speed;

when said sensed element is in the second position, the motor is actuated to run at the no load speed; and

, when the sensed element is in an intermediate position between the first and second positions, the motor is actuated to run at an intermediate speed between the slow speed and the no load speed; and

said control member includes a leg positioned adjacent said sensed element to displace said sensed element upon movement of said control member and said leg is shaped so that, when said control member is moved to the final position, said leg displaces said sensed element to one of the intermediate positions located between the first and second sensed element positions.

5. The powered surgical saw of claim 1, wherein said speed limiting assembly is associated with said speed regulator.

6. The powered surgical saw of claim 5, wherein:

said speed regulator includes a sensor configured to monitor the position of said control member, said sensor configured to generate a variable speed signal as a function of the position of said control member wherein when said control member is in the second limit position, said sensor generates a full speed speed signal;

said speed limiting assembly comprises a signal attenuator connected to said sensor for receiving said speed signal and producing a modified speed signal based on said speed signal; and

said speed regulator is further configured to receive the modified speed signal and cause said motor to operate at a motor speed that is a function of the modified speed signal, wherein based on the modified speed signal received when said sensor produces the full speed speed signal, said speed regulator causes said motor to run at the maximum motor speed.

7. The powered surgical tool of claim 1, wherein said speed regulator is configured to hold the motor speed at a constant speed as a function of movement of said control member when the load applied to said motor varies.

10. The powered surgical tool of claim 7, wherein:

said control member and said sensed member are separate, independently moveable components, and said sensed member is disposed in said handpiece; and

said control member includes a driver disposed in said handpiece, said driver is connected to said sensed member to move said sensed member upon displacement of said control member and said drive is connected to said sensed member so that complete displacement of said control member does not result in displacement of said sensed member from the sensed member first limit position to the sensed member second limit position.

8. A powered surgical tool comprising:

a handpiece;

a variable speed motor disposed in said handpiece, said motor being configured to operate at a select speed in response to the application of a select actuation signal to said motor;

a coupling assembly moveably connected to said handpiece for removably receiving a cutting accessory;

a linkage assembly extending between said motor and said coupling assembly for transferring the rotary motion developed by said motor to said coupling assembly so that, in response to actuation of said motor, said coupling assembly and the cutting accessory attached to said coupling assembly engage in motion;

a battery connected to said handpiece for supplying electrical energy to said motor;

a control assembly attached to said handpiece;

said control assembly including;

a user-actuated control member moveably attached to said handpiece;

a sensed member connected to said control member to move upon displacement of said control member, said sensed member having a first limit position, a second limit position and being selectively positionable between said limit positions; and

a stop assembly associated with said control member positioned to restrict movement of said sensed member so that said member is blocked from moving to the sensed member second limit position;

a motor regulator, said motor regulator connected to said motor and said battery for selectively applying the actuation signal to said motor, said motor regulator being configured to apply the actuation signal to said motor so that said motor can operate at speeds up to a no load speed;

a speed regulator integral with said motor regulator, said speed regulator connected to said motor to monitor the speed of said motor, said speed regulator including a sensing assembly for monitoring the displacement of said sensed member, said sensing assembly generating a user speed signal representative of user selected speed based on the displacement of said sensed member, and said speed regulator is configured to, based on the movement of the sensed element and motor speed, control the application of the actuation signal to said motor by said motor regulator as the load applied to said motor varies so that said motor runs at a user selected speed and is further configured so that, when sensed member moves in the direction of the second limit position, said speed regulator causes said motor to run at a maximum speed, the maximum speed being less than the motor no load speed.

9. The powered surgical tool of claim 8, wherein said stop assembly includes a member attached to said handpiece that is positioned to abut said control member when said control member is moved to displace said sensed member in the second limit position.

11. The powered surgical tool of claim 9, wherein said control member driver is a leg positioned to abut said sensed member upon displacement of said driver and said leg is shaped so that the complete displacement of said control member does not result in said leg displacing said sensed member to the sensed member second limit position.

12. A powered surgical tool comprising:

a handpiece;

a variable speed motor disposed in said handpiece, said motor being configured to operate at a select speed in response to the application of a select actuation signal to said motor, said motor having a no load speed;

a coupling assembly moveably connected to said handpiece for removably receiving a cutting accessory;

a linkage assembly extending between said motor and said coupling assembly for transferring the rotary motion developed by said motor to said coupling assembly so that, in response to actuation of said motor, said coupling assembly and the cutting accessory attached to said coupling assembly engage in motion;

a battery connected to said handpiece for supplying electrical energy to said motor;

a control member moveably attached to said handpiece, said control member having a first limit position, a second limit position and a plurality of intermediate positions between the limit positions, and a motor regulator disposed in said handpiece, said motor regulator connected to;

said battery;

said motor for applying the actuation signal to said motor and for monitoring the speed of said motor; and

to monitor the position of said control member, said motor regulator being configured to, based on the position of said control member and the speed of said motor, regulate the application of the actuation signal to said motor so that said motor runs at a select speed based on the position of said control member and, wherein the speed of said motor is increased as said control member moves from the first limit position towards the second limit position and, when said control member is in a second limit position, said motor regulator applies the actuation signal to said motor so that said motor runs at a maximum speed, the maximum speed being less than the motor no load speed.

13. The powered surgical tool of claim 12, wherein said motor regulator includes:

a speed regulator internal to said motor regulator for regulating the application of the actuation signals to said motor so that said motor can operate at variable speeds up to the no load speed, said speed regulator being connected to said motor for monitoring the speed of said motor and receiving a speed signal as an indication of user selected speed for the motor and being configured to control the application of the actuation signal to said motor, wherein, based on the speed signal, said speed regulator can cause said motor to operate at the no load speed;

a sensor circuit that monitors the position of said control member, and said sensor signal generates a variable sensor signal as a function of the position of said control member;

a speed limit circuit connected to said sensor circuit for receiving said sensor signal that, as a function of the sensor signal, produces the speed signal for application to said speed regulator, and is configured to produce, at a maximum, a speed signal that indicates said motor is to be operated at the maximum speed.

14. The powered surgical tool of claim 13, wherein said sensor is a magnetic field sensor.

15. The powered surgical tool of claim 13, wherein said speed limit circuit is a voltage divider to which said sensor signal is applied.

16. A powered surgical tool, said tool comprising:

a handpiece;

a power generating unit disposed in said handpiece, said power generating unit configured to generate a variable amount of power

a coupling assembly attached to said handpiece, said coupling assembly configured to releasably receive a cutting accessory and transfer the power generated by said power generating unit to said cutting accessory;

a control member moveably attached to said handpiece, wherein said control member is attached to said handpiece to be selectively placed in a first or second orientation relative to a reference point on said handpiece and so that when in the first or second orientation, at least a section of said control member is able to be selectively positioned relative to the reference point;

a sensor assembly disposed in said handpiece, said sensor assembly including;

at least one first sensor configured to monitor the orientation of said control member that generates a first sensor output signal representative of the orientation of said control member; and

a second sensor configured to monitor the movement of said control member relative to the reference point that generates a second sensor signal representative of the relative position of said control member; and

a power regulator connected to said sensor assembly to receive the first and second sensor signals and to said power generating unit for regulating the amount of power generated by said power generating unit, said power regulator being configured so that;

when the first and second sensors indicate that said control member is in the first orientation relative to the reference point and in a first position relative to the reference point, said power regulator causes said power generating unit to produce a first amount of power; and

when the first and second sensors indicate that said control member is in the second orientation relative to the reference point and in the first position relative to the reference point, said power regulator causes said power generating unit to produce a second amount of power that is different from the first amount of power.

17. The powered surgical tool of claim 16, wherein:

said power generating unit is a variable speed motor; and

said power regulator is a speed regulator that is connected to said motor for regulating the speed of said motor, and is configured so that;

when the first and second sensors indicate that said control member is in the first orientation relative to the reference point and in a first position relative to the reference point, said speed regulator causes said motor to run at a first speed; and

when the first and second sensors indicate that said control member is in the second orientation relative to the reference point and in the first position relative to the reference point, said speed regulator causes said motor to run at a second speed, the second speed being different from said first speed.

18. The powered surgical tool of claim 16, wherein:

said control member is rotatably attached to said handpiece and is further attached to said handpiece so that at least a portion of said control member is moveable so as to be selectively positionable relative to the handpiece reference point; and

said sensor assembly first sensor is configured to monitor the rotation orientation of said control member relative to said handpiece.

19. The powered surgical tool of claim 16, wherein:

said control member is rotatably attached to said handpiece and is further attached to said handpiece so as to be selectively retracted or extended relative to said handpiece;

said sensor assembly first sensor is configured to monitor the rotational orientation of said control member relative to said handpiece; and

said sensor assembly second sensor is configured to monitor the extent to which said control member is retracted/extended relative to said handpiece.

20. The powered surgical tool of claim 16, wherein:

said first sensor includes;

first and second carriages that are disposed in said handpiece and are independently moveable;

a first linkage member attached to said control member to move said first carriage when said control member is in the first orientation and said control member is positioned relative to the handpiece reference point; and

a second linkage member attached to said control member to move said second carriage when said control member is in the second orientation and said control member is positioned relative to the handpiece reference point;

wherein, said first sensor linkage members are configured so that;

when said control member is in the first orientation and is moved to the first position relative to the handpiece reference point, said first carriage is displaced a first distance and, when said control member is in the second orientation and is moved to the first position relative to the handpiece reference point, said second carriage is displaced a second distance, the second distance being different from the first distance; and

said second sensor includes a third carriage that is moveably disposed in said handpiece and said first and second carriages are positioned to displace said third carriage, said first carriage being able to displace said third carriage a distance proportional to the distance said first carriage is displaced and second carriage being able to displace said third carriage a distance proportional to the distance said second carriage is displaced.

21. The powered surgical tool of claim 16, wherein said first sensor includes:

first and second carriages that are disposed in said handpiece and are independently moveable;

a first linkage member attached to said control member to move said first carriage when said control member is in the first orientation and said control member is positioned relative to the handpiece reference point;

a second linkage member attached to said control member to move said second carriage when said control member is in the second orientation and said control member is positioned relative to the handpiece reference point; and

first and second carriage sensors, said first carriage sensor configured to monitor the movement of said first carriage and to generate a first carriage signal representative of the displacement of said first carriage and said second carriage configured to monitor the movement of said second carriage and to generate a second carriage signal representative of the displacement of said second carriage, wherein the first and second carriage signals collectively form the first sensor signal.

22. The powered surgical tool of claim 16, wherein said first and second sensors are separate components.

23. The powered surgical tool of claim 16, wherein at least one of said first or second sensors is configured to monitor magnetic field strength.

24. The powered surgical tool of claim 16, wherein:

said first sensor and said second sensor collectively comprise a first sensing unit and a second sensing unit;

said first sensing unit is configured to generate a variable first sensing unit signal representative of the position of said control member relative to the handpiece reference point when said control member is in the first orientation;

said second unit is configured to generate a variable second sensing unit signal representative of the position of said control member relative to the handpiece reference point when said control member is in the second orientation so that the first and second sensing unit signals collectively function as said first and second sensor signals.

25. The powered surgical tool of claim 24, wherein said first and second sensing units are configured to measure magnetic field strength.